In its announcement, the USDA notes that cases of mad cow disease worldwide have decline dramatically:

Evidence shows that our systems and safeguards to prevent BSE are working, as are similar actions taken by countries around the world. In 2011, there were only 29 worldwide cases of BSE, a dramatic decline and 99% reduction since the peak in 1992 of 37,311 cases. This is directly attributable to the impact and effectiveness of feed bans as a primary control measure for the disease.

The USDA also found that this particular cow had a "very rare" form of the disease that, unlike most cases of mad cow disease, wasn't transmitted through the animal's feed.

So don't panic.

For an infinitely more charming cow-related story, let's travel to Colorado.